As used herein, the term “membrane switch” means a switch including a plurality of conductive regions with at least one of the conductive regions located on a layer of flexible material.
Current membrane switches may include a first conductive region on a first layer of material aligned over a second conductive region on a second layer of material. A flexible material may be used for one or both of the first and second layers. One of the conductive regions may include interdigitated fingers forming a pair of terminals for the switch. Normally, the conductive regions do not make contact with each other and the switch is open. When a user presses one of the conductive regions such that the two conductive regions touch, a circuit is completed across the interdigitated fingers to close the switch. A spacer material is typically located between the two layers to prevent inadvertent contact of the conductive regions and switch closure. Apertures in the spacer material leave exposed the conductive regions, so they may be selectively engaged to close the switch. The thickness of the spacer material is typically in the range of 0.006 inches to 0.012 inches.
Reducing the thickness of the spacer material may improve the feel of the switch to the user. For example, by reducing the thickness of the spacer material, the touching of a conventional membrane switch to close the switch may feel to the user more like touching of a capacitive touch switch, which is a higher-end, more expensive switch. However, it is currently impractical to reduce the spacer material thickness in a membrane switch below the currently-employed range, because in doing so, one would cause inadvertent switch operation due to temperature and/or pressure gradients.
Thus, there was a need to overcome these and other limitations in membrane switches, whether the improvements thereof are employed in membrane switches or in any other switch design.